1. Field of the Invention
The present invention relates to an operation microscope apparatus which allows a front lens of an operation microscope to be disposed in front of an objective lens and which supports the operation microscope to an operation microscope support portion to enable upward and downward movement of the operation microscope by an electrically-operated elevating device.
2. Description of the Related Art
Up to now, there has been known an operation microscope system of a swing type in which a first arm is mounted on an upper end portion of a pillar so as to be horizontally rotatable, one end portion of a second arm (operation microscope support portion) is mounted to a free end portion of the first arm so as to be horizontally rotatable and swingable upward and downward, and an operation microscope is mounted to the other end portion of the second arm through an electrically-operated upward-and-downward micro-motion device (for example, JP laid-open No. 06-022980 A).
Also, there has been known an operation microscope in which a front lens is disposed in front of an objective lens of an observation optical system to observe an eye to be examined through the observation optical system and the front lens (for example, JP laid-open No. 2002-350735 A).
Now, when the operation microscope is not used in the above-mentioned operation microscope system, the operation microscope is substantially retreated upward from the vicinity of an observation region. In this case, if the front lens is disposed on the front side (lower side) of the objective lens, the front lens hinders the observation. Therefore, the front lens is supported by a holding arm such that the front lens can be removed from the front side (lower side) of the objective lens and retreated upward.
In such an apparatus for the operation microscope having the front lens, when the operation microscope is more roughly moved upward and downward with the front lens at a use position, it is necessary to sufficiently ensure the safety.
Here, “rough motion” means to be displaced roughly, “micro motion” means to be displaced finely.